KR102242863B1 - Display device with touch panel - Google Patents

Abstract

The present invention relates to a display device having a touch panel, and in particular, when it is determined that there is a touch by a pen, the driving mode of the touch panel is converted to a pen mode, and then the recognition rate of the touch by the pen can be increased. , It is a technical task to provide a display device with a touch panel capable of changing touch recognition conditions.

Description

Display device with touch panel {DISPLAY DEVICE WITH TOUCH PANEL}

The present invention relates to a display device, and more particularly, to a display device including a touch panel.

Flat panel displays (FPDs) (hereinafter simply referred to as'display devices') are used in various types of electronic products including mobile phones, tablet PCs, and notebook computers. Flat panel display devices include a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting display device (OLED), and more recently, an electrophoretic display device. (EPD: ELECTROPHORETIC DISPLAY) is also widely used.

A touch panel is a type of input device that is installed on a display device and allows a user to directly touch a screen with a finger or a pen while viewing the display device to input information.

As a method of sensing a touch, there is a method of sensing a touch using a change in capacitance. In the capacitive method, when a human body or a conductive material comes into contact with the touch panel, a change in capacitance is sensed to determine the presence or absence of a touch, and then the touch coordinates are determined.

The capacitive method can also be applied to a method of determining the presence or absence of a touch by a pen. For example, when there is a conductive material in the pen, the presence or absence of a touch may be determined using a change in capacitance between the pen and the touch panel.

Accordingly, a user using a display device having a touch panel using a capacitive method can input information by touching a pen or a finger to the touch panel.

However, when a user who uses a conventional display device equipped with a capacitive touch panel puts his or her palm on the touch panel to use a pen or holds the touch panel with both hands, a touch error occurs.

In order to eliminate such errors, a conventional display device equipped with a capacitive touch panel implements a palm rejection function. According to the palm rejection function, even if the palm touches the touch panel, the touch by the palm is not recognized as a normal touch.

To further explain, a conventional display device having a palm rejection function analyzes the raw data transmitted from the touch panel to detect the presence or absence of a touch, and if there is a touch, the touch is caused by the palm by using the palm rejection function. It is determined whether or not it is a touch. As a result of the determination, if the touch is by the palm, the display device does not recognize the touch by the palm as a touch, but determines the presence or absence of the touch by the pen. If the touch is not by the palm, the display device responds to the touch. Judging the coordinates for each.

However, a conventional display device provided with a capacitive touch panel has a limitation in implementing dynamic palm rejection. For example, in a conventional display device, when a touch by a palm moves when a touch by a pen is input, the touch by the palm cannot be completely removed.

In addition, in the conventional display device equipped with a capacitive touch panel, when a user touches the touch panel with a pen, when a small area of the palm touches the touch panel, the small area of the palm is touched by a finger. It can also be recognized as. That is, the touch by the palm may be determined as the touch by the finger.

In addition, in a conventional display device equipped with a capacitive touch panel, when the touch by the pen and the touch by the palm are adjacent, the touch by the pen is mistaken as the touch by the palm, and the touch by the pen is You may not be able to recognize it by touch.

To further explain, in a conventional display device including a capacitive touch panel, a touch by a palm is classified using an area and a shape of a touched area. Accordingly, when a user contacts the palm or elbow with the touch panel while using the pen, if the contact surface is small, an error in which the touch by the palm or elbow is determined to be a normal touch may occur.

In addition, in a conventional display device equipped with a capacitive touch panel, since the pen mode and the finger mode are not distinguished, when a touch by a pen and a touch by a palm are simultaneously input, only the touch by the pen is accurately It is difficult to judge.

The present invention is to solve the above-described problem, and if it is determined that there is a touch by a pen, after converting the driving mode of the touch panel to the pen mode, the touch recognition condition so that the recognition rate of the touch by the pen can be increased. It is a technical problem to provide a display device having a touch panel capable of changing the display devices.

A display device provided with a touch panel according to the present invention for achieving the above object includes: a touch panel on which touch electrodes are formed; A touch sensing unit supplying a touch driving signal to the touch panel in a finger mode, receiving sensing signals based on the touch driving signal from the touch panel, and converting the sensing signals into raw data having a digital value; And analyzing the raw data to determine whether or not there is a touch by the pen, and when it is determined that there is a touch by the pen, the driving mode of the touch panel is switched from the finger mode to the pen mode, and the And a touch determination unit that determines a touch coordinate in which a touch is generated on the touch panel.

According to the present invention, a finger mode and a pen mode can be classified, and in the pen mode, the presence or absence of a touch by the pen can be more accurately determined. Therefore, the touch sensitivity by the pen can be improved.

In addition, in the pen mode, since the touch by the palm can be accurately determined and removed, the user can touch the touch panel using the pen in a more comfortable posture.

1 is an exemplary view showing a configuration of a display device including a touch panel according to the present invention.
2 is a block diagram showing the configuration of a display device having a touch panel according to an embodiment of the present invention.
3 is an exemplary view showing a configuration of a touch determination unit applied to a display device equipped with a touch panel according to the present invention.
4 is a flowchart illustrating a method of driving a display device having a touch panel according to an exemplary embodiment of the present invention.
5 is an exemplary view illustrating a method of determining a pen mode by a display device equipped with a touch panel according to the present invention.
6 is an exemplary view illustrating a method in which only a touch by a pen is sensed by a display device having a touch panel according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary view showing the configuration of a display device with a touch panel according to the present invention, FIG. 2 is a block diagram showing the configuration of a display device with a touch panel according to the present invention, and FIG. 3 is An exemplary view showing a configuration of a touch determination unit applied to a display device having a touch panel according to the present invention.

1 and 2, a display device having a touch panel according to the present invention includes a panel 100 for displaying an image, and a touch panel formed on the panel 100 and on which touch electrodes are formed. 500), supplying a touch driving signal to the touch panel 500 in a finger mode, receiving sensing signals by the touch driving signal from the touch panel 500, and receiving the sensing signals as raw data having a digital value A touch sensing unit 600 that converts into a touch sensor 600 that analyzes the raw data to determine whether there is a touch by a pen, and when it is determined that there is a touch by a pen, sets the driving mode of the touch panel 500 to a pen in the finger mode A touch determination unit 410 that converts to a mode and determines a touch coordinate in which a touch is generated in the touch panel 500 by using the raw data, and gate lines GL1 to GLg formed in the panel 100. A gate driver 200 sequentially supplying scan pulses to ), a data driver 300 supplying data voltages to data lines DL1 to DLd formed in the panel 100, and the gate driver 200 And a control unit 400 for controlling functions of the data driver 200 and the touch sensing unit 600 and the touch determination unit 410.

First, the panel 100 may be various types of panels such as a liquid crystal panel, an organic light emitting panel, or an electrophoretic display panel.

The panel 100 is formed by bonding a first substrate and a second substrate. An intermediate layer is formed between the first substrate and the second substrate.

The first substrate and the second substrate may be made of glass, plastic, metal, or the like.

The intermediate layer may have different configurations according to the type of the display device including the touch panel according to the present invention. For example, when the display device including the touch panel according to the present invention is a liquid crystal display device (LCD), the intermediate layer may include a liquid crystal. When the display device including the touch panel according to the present invention is an organic light emitting display device (OLED), the intermediate layer may include an organic compound that outputs light. When the display device provided with the touch panel according to the present invention is an electrophoretic display device (EPD), the intermediate layer may include an electrophoretic dispersion or the like.

Hereinafter, for convenience of description, a liquid crystal display will be described as an example of the present invention, but the present invention is not limited thereto. That is, the present invention can be applied to various types of display devices to which various types of touch panels are applied.

When the panel 100 is a liquid crystal panel, a first substrate (TFT substrate) of the panel 100 includes a plurality of data lines DL1 to DLd and a plurality of gate lines crossing the data lines ( GL1 to GLg), thin film transistors (TFTs) formed in pixels formed at intersections of the data lines and the gate lines, and data formed in each of the pixels Pixel electrodes for charging a voltage and common electrodes for driving a liquid crystal charged in the pixel are formed together with the pixel electrode. That is, the pixels are arranged in a matrix form in each area where the data lines DL1 to DLd and the gate lines GL1 to GLg intersect, and each of the pixels includes the TFT, the pixel electrode, and the A common electrode is formed.

When the panel 100 is a liquid crystal panel, a black matrix (BM) and a color filter are formed on the second substrate (CF substrate) of the panel 100.

Second, the data driver 300 converts the image data input from the control unit 400 into a data voltage, and converts the data voltage for one horizontal line into the data line for every horizontal period in which a scan pulse is supplied to the gate line. To the field. That is, the data driver 300 converts the image data into a data voltage using gamma voltages supplied from a gamma voltage generator (not shown) and outputs the converted image data to the data lines.

The data driver 300 shifts a source start pulse (SSP) transmitted from the control unit 400 according to a source shift clock (SSC) to generate a sampling signal. Further, the data driver 300 latches the image data RGB input according to the source shift clock SSC according to the sampling signal, changes it to the data voltage, and then enables the source output. In response to an Output Enable (SOE) signal, the data voltage is supplied to the data lines in units of horizontal lines.

To this end, the data driver 300 may include a shift register unit, a latch unit, a digital to analog conversion unit, and an output buffer.

Third, the gate driver 200 shifts the gate start pulse (GSP) transmitted from the control unit 400 according to a gate shift clock (GSC), and sequentially shifts the gate lines ( A scan pulse having a gate-on voltage Von is supplied to GL1 to GLg. In addition, the gate driver 200 supplies a gate-off voltage Voff to the gate lines GL1 to GLn during the remaining period when the scan pulse having the gate-on voltage Von is not supplied.

Although the data driver 300 and the gate driver 200 have been described as being independently configured, at least one of the data driver 300 and the gate drivers 200 may be configured in the control unit 400. .

Fourth, the touch panel 500 uses a capacitive method, is formed on the panel 100, and includes a plurality of touch electrodes.

The touch electrodes are connected to the touch sensing unit 600 through touch electrode lines TL1 to TLk.

In the display device using the capacitive touch panel 500, when a person's body or a conductive material contacts the touch panel 500, a change in capacitance is sensed to determine the presence or absence of a touch. Determine the exact coordinates. In a display device using the capacitive type touch panel 500, the touch panel 500 can be used to determine not only the presence of a touch by a user's finger, but also the presence of a touch by a pen. As described above, the pen applied to the present invention is equipped with a conductive material capable of changing the capacitance.

The touch panel may be formed on the panel 100 in an in-cell type, an add-on type, or a hybrid in-cell type.

In the in-cell type touch panel, the touch electrodes are embedded in the panel 100. In this case, the touch electrodes may be formed of common electrodes formed on the panel 100, and may be formed of a gate line or a data line formed on the panel 100 in addition to the common electrodes.

The add-on type touch panel is manufactured independently from the panel 100 that outputs an image, and then attached to the panel 100. In this case, the touch panel 500 may be attached to the panel 100 by an adhesive portion such as UV resin, OCR (Optically Clear Resin), or OCA (Optically Clear Adhesive). That is, the touch panel 500 may be manufactured separately from the panel 100 and then bonded to the panel 100.

In the hybrid in-cell type touch panel, some of the touch electrodes constituting the touch panel are formed on the first substrate and the rest are formed on the second substrate.

In addition, the touch panel 500 may be configured in a mutual method or a self-cap method.

The touch panel 500 using the mutual method includes driving electrodes supplied with a touch driving signal and receiving electrodes transmitting a sensing signal generated by the touch driving signal to the touch sensing unit 600. The driving electrodes and the receiving electrodes are collectively referred to as a touch electrode.

The touch panel 500 using the self-cap method is formed in a block shape. The touch panel 500 includes a plurality of touch electrodes receiving a touch driving signal from the touch sensing unit 600 and transmitting sensing signals to the touch sensing unit 600.

To further explain, the touch panel 500 of a mutual method or a self-cap method receives the touch driving signal from the touch sensing unit 600, and the touch sensing unit 600 receives sensing signals by the touch driving signal. ).

Fifth, the control unit 400 receives timing signals such as a data enable signal (Data Enable, DE) and a dot clock (CLK) from the external system 900, and the data driver 300 and the gate driver 200 It generates control signals (GCS, DCS) for controlling the operation timing of ).

The gate control signals GCS generated by the controller 400 include a gate start pulse GSP, a gate shift clock GSC, and a gate output enable signal GOE.

The data control signals DCS generated by the control unit 400 include a source start pulse (SSP), a source shift clock signal (SSC), a source output enable signal (SOE), a polarity control signal (POL), and the like. do.

In addition, the controller 400 rearranges the input image data input from the external system 900 and outputs the rearranged image data to the data driver 300.

The controller 400 may control the touch sensing unit 600 by generating a touch control signal for controlling an operation timing of the touch sensing unit.

For example, when the touch panel is embedded in the panel 100, the control unit 400 controls the touch so that an image output period in which an image is output and a touch detection period in which a touch is sensed can be repeated. A signal may be generated and transmitted to the touch sensing unit 600.

In addition, the control unit 400 may transmit a touch mode control signal for driving the touch sensing unit 600 in the pen mode or the finger mode to the touch sensing unit.

The touch sensing unit 600 is driven in the pen mode or the finger mode according to the touch mode control signal.

The touch mode control signal may be generated by the control unit 400 according to a signal transmitted from the touch determining unit 410 and transmitted to the touch sensing unit 600.

However, the touch determination unit 410 may directly generate the touch mode control signal and transmit it to the touch sensing unit 600.

In order to perform the functions as described above, the controller 400 receives the input image data and various timing signals as described above from the external system 900, as shown in FIG. 2, and the touch A transmission/reception unit 440 for transmitting the touch coordinate determined by the determination unit 410 to the external system 900 and the input image data among signals received from the transmission/reception unit 440 are transferred to the panel 100. The gate driver 200 and the data driver are re-arranged accordingly and using an image data processing unit 430 for transmitting the rearranged digital image data to the data driver 300 and timing signals received from the transmission/reception unit. 300) and the gate control signal GCS for controlling the touch sensing unit 600, the data control signal DCS, and a control signal generator 420 for generating the touch control signals.

The control signal generation unit 420 may generate the touch mode control signal according to a signal transmitted from the touch determination unit 410 and transmit the touch mode control signal to the touch sensing unit 600.

Sixth, the touch determination unit 410 analyzes the raw data received from the touch sensing unit 600 to determine whether there is a touch by a pen, and when it is determined that there is a touch by the pen, the touch panel 500 ) Converts the driving mode from the finger mode to the pen mode, and determines a touch coordinate in which a touch is generated in the touch panel 500 by using the raw data.

To this end, the touch determination unit 410 selects the pen mode or the finger mode by analyzing the raw data, as shown in FIG. 3, and according to the selection, the touch sensing unit 600 A mode determination unit 411 that transmits the touch mode control signal to be driven in the pen mode or the finger mode to the touch sensing unit 600, and analyzes the raw data so that the touch panel 500 is And a touch coordinate determination unit 412 for determining the touch coordinates touched by and a communication unit 413 for transmitting the touch coordinates to the external system 900.

The mode determination unit 411 determines the presence or absence of a touch by a pen using a distribution of the size of the raw data, and selects the pen mode or the finger mode according to the determination result.

The mode determination unit 411 may generate and transmit the touch mode control signal to the touch sensing unit 600 so that the touch sensing unit 600 may be driven according to the selected driving mode.

However, the touch mode control signal may be generated by the control unit 400, in particular, the control signal generation unit 420. For example, the mode determination unit 411 may transmit a control signal for generating the touch mode control signal corresponding to the selected driving mode to the control signal generation unit 420, and the control signal generation unit 420 ) May generate the touch mode control signal according to the control signal received from the mode determination unit 411 and then transmit the touch mode control signal to the touch sensing unit 600.

Hereinafter, the present invention will be described with the case where the mode determination unit 411 directly generates the touch mode control signal and transmits it to the touch sensing unit 600 as an example.

After the pen mode is selected, the mode determination unit 411 may switch the driving mode to the finger mode when it is determined that there is no touch by the pen for a preset period.

That is, when the mode determination unit 411 is set to the automatic mode, the mode determination unit 411 automatically drives the drive when it is determined that there is no touch by the pen for a preset period after the pen mode is selected. The mode can also be switched to the finger mode.

When the mode change signal is received from the external system 900 while the pen mode is selected, the mode determination unit 411 may switch the driving mode to the finger mode.

For example, when the mode conversion signal is received by the external system 900 through a button or menu through which a user can select a manual mode, the external system 900 transmits the mode conversion signal to the communication unit ( It is transmitted to the mode determination unit 411 through 413. When the mode change signal is received, the mode determination unit 411 converts the pen mode to the finger mode, and then the touch mode control signal to enable the touch sensing unit 600 to be driven in the finger mode. Is generated and transmitted to the touch sensing unit 600.

The touch coordinate determination unit 412 may determine a touch coordinate touched by a pen or a finger using the raw data transmitted from the touch sensing unit 600.

The communication unit 413 may transmit the touch coordinates to the external system 900. In addition, the communication unit 413 may receive the mode conversion signal transmitted from the external system 900 and transmit it to the mode determination unit 411.

The touch determination unit 410 may be integrally formed with the touch sensing unit 600, or may be formed independently of the touch sensing unit 600, and as shown in FIG. 2, the control unit ( 400).

Seventh, the touch sensing unit 600 generates the raw data using sensing signals received from the touch panel, and then transmits the raw data to the touch determination unit 410.

For example, in the mutual type touch panel 500, when a touch driving signal for detecting a touch is sequentially supplied to the driving electrodes among the touch electrodes, the user touches the touch with a finger or a pen. When a specific area of the panel 500 is touched, capacitance between the driving electrodes and the receiving electrodes changes. The change in capacitance changes the size of the sensing signals transmitted from the receiving electrode to the touch sensing unit 600 among the touch electrodes. The touch sensing unit 600 converts sensing signals received from the receiving electrodes into the raw data having a digital value and transmits the converted data to the touch determination unit 410.

In the self-cap type touch panel 500, when a user touches a specific area of the touch panel 50 with a finger or a pen when a touch driving signal for detecting a touch is simultaneously supplied to the touch electrodes, The capacitance charged to the touch electrode or the time during which the preset capacitance is charged to the touch electrode varies. This change changes the size or shape of the sensing signals. The touch sensing unit 600 converts sensing signals received from the touch electrodes into the raw data having a digital value and transmits the converted data to the touch determination unit 410.

To further explain, the touch sensing unit 600 converts the sensing signals, which are analog signals, into the raw data, which are digital signals, and then converts the raw data to the touch determination unit 410. ), and the touch determination unit 410 determines whether a touch is present or a touch position.

In order to perform the functions as described above, the touch sensing unit 600 generates the touch driving signal and receives the sensing signals from the touch electrodes. And a touch receiving unit 620 for converting the sensing signals into the raw data and transmitting them to the touch pandanu 410, and a touch control unit 630 for changing the touch drive signal according to the touch mode control signal. do.

In particular, the touch sensing unit 600, when the touch mode control signal means the pen mode, the touch drive signal having a frequency or voltage level greater than the frequency or voltage level of the touch drive signal in the finger mode. It may perform a function of generating and supplying it to the touch panel. To this end, the touch control unit 630 may control the touch driving unit 610.

In addition, when the touch mode control signal means the pen mode, the touch sensing unit 600 generates the raw data after amplifying the size of the detection signal, or the detection signal using a low pass filter. After filtering is performed, the raw data is generated, and the generated raw data is transmitted to the touch determination unit. To this end, the touch control unit 630 may control the touch receiving unit 620.

Eighth, the external system 900 is an electronic product such as a TV, a monitor, a tablet PC, a smartphone, or an electronic blackboard (hereinafter simply referred to as'image system') equipped with a display device equipped with a touch panel according to the present invention. It is a system that drives). For example, when the image system is a tablet PC, the image system includes a display device including a touch panel according to the present invention and the external system 900.

Hereinafter, a method of driving a display device including a touch panel according to the present invention will be described with reference to FIGS. 1 to 6.

4 is a flowchart illustrating a method of driving a display device equipped with a touch panel according to an embodiment of the present invention, and FIG. 5 is a flowchart illustrating a method of determining a pen mode by a display device equipped with a touch panel according to the present invention. It is an exemplary diagram, and FIG. 6 is an exemplary diagram for explaining a method of detecting only a touch by a pen by a display device having a touch panel according to the present invention. Hereinafter, the same or similar content as described above will be omitted or briefly described.

First, a display device including a touch panel according to the present invention is driven in a finger mode.

In the finger mode, the touch sensing unit 600 and the touch determination unit 410 perform the same functions as the touch sensing unit 600 and the touch determination unit of a display device equipped with a general touch panel that is currently being used. Thus, after determining the touch coordinates by the user's finger, the determined touch coordinates are transmitted to the external system 900.

In this case, when touch coordinates having a larger area than a finger are extracted, the touch determination unit 600 determines that the touched area has been touched by a palm or elbow, and the extracted touch coordinates are converted to the external system 900. May not be transmitted. This function is called the Palm Rejection function. That is, the palm rejection function may also be executed in the finger mode.

Next, in the finger mode, the touch determination unit 410 determines whether there is a touch by a pen (S302). The mode determination unit 411 determines the presence or absence of a touch by a pen using a distribution of the size of the raw data, and selects the pen mode or the finger mode according to the determination result.

The determination of the presence or absence of a touch by the pen may be made continuously during the finger mode, but may be made every preset period.

For example, the determination of the presence or absence of a touch by the pen may be performed at least every one frame period.

The determination of the presence or absence of a touch by the pen is performed using a method as shown in FIG. 5.

First, when the touch determination unit 410 detects, in the finger mode, raw data exceeding a threshold value (for example, 150) that can be recognized as a touch (hereinafter, simply referred to as'reference raw data'), As shown in FIG. 5, 5x5 row data is stored based on the touch electrode (hereinafter, simply referred to as “reference touch electrode”) X, in which the reference row data is detected.

Second, the touch determination unit 410 determines whether the raw data around the reference touch electrode X form a predetermined specific pattern.

For example, since the area of the reference touch electrode is generally larger than the area of the pen, the pen is in contact with a part of the reference touch electrode. Further, even if the pen contacts the reference touch electrode, touch electrodes around the reference touch electrode are also affected by the pen. Accordingly, raw data may also be received from touch electrodes around the reference touch electrode.

In this case, depending on the position where the pen is in contact with the reference touch electrode, the size of the raw data received from the touch electrodes around the reference touch electrode may be different. The size of the received raw data gets smaller as it goes to the electrode.

As a more specific example, referring to the raw data shown in FIG. 5, the raw data of the eight touch electrodes surrounding the reference touch electrode X are 118, 57, 83, 35, 68, and 36 in a clockwise direction, respectively. , 75, and 47, which are smaller than the reference raw data.

Further, the raw data of the touch electrodes outside the eight touch electrodes are gradually decreasing as the distance from the reference touch electrode X increases.

In particular, it can be seen that among the eight touch electrodes, the raw data of the touch electrode to the left of the reference touch electrode X is larger than that of the other seven touch electrodes.

Based on the analysis results as described above, it can be seen that the reference touch electrode X is touched by a pen, and the pen is, among the reference touch electrodes X, in particular, the left region of the reference touch electrode X. You can see that you are touching.

If the reference raw data is caused by a finger, the raw data of at least one touch electrode has raw data higher than a threshold value. However, as shown in FIG. 5, it is understood that the reference touch electrode X is touched by a pen because the neighboring raw data are sequentially decreasing based on the one reference touch electrode X. I can.

The touch determination unit 410 may determine that the reference touch electrode X is touched by a pen by performing the analysis as described above.

In more detail, when the pattern as described above is formed based on the reference touch electrode X, the touch determination unit 410 may determine that the reference touch electrode X has been touched by a pen. I can.

Third, if it is determined that the reference touch electrode X has been touched by a pen (S302), the touch determination unit 410 converts the driving mode to the pen mode, and then the touch sensing unit changes to the pen mode. A touch mode control signal to be driven is generated and transmitted to the touch sensing unit 600.

Next, as a result of the determination (S302), when a touch by a pen is sensed, the touch determination unit 410 and the touch sensing unit 600 determine a touch coordinate in the pen mode (S304).

For example, when the driving mode is switched to the pen mode, the touch determination unit 410 amplifies the size of the raw data or filters the raw data using a low pass filter, and the amplified The touch coordinates touched by the pen may be determined using the raw data or the raw data passing through the low pass filter.

In addition, when the touch mode control signal means the pen mode, the touch sensing unit 600 has a frequency or number or voltage level greater than the frequency or number or voltage level of the touch drive signal in the finger mode. A touch drive signal may be generated and supplied to the touch panel.

The above example will be described in detail as follows.

First, in the pen mode, the touch sensing unit 600 or the touch determination unit 410 may process the sensing signals using a low pass filter (LPF), and accordingly, the pen The touch by may be more accurately determined.

The reason for using the low pass filter is as follows.

For example, when a touch is sensed by a pen, the touch drive signal is small. Therefore, in order to slightly facilitate the discrimination between a small noise similar to a touch by a pen and a sensing signal received by the pen, a low pass filter is used.

The low pass filter may be used alone.

Further, according to the low pass filter, both the detection signal and noise by the pen may be removed. Therefore, conditions of the low pass filter must be set through various tests and simulations. For example, in consideration of other conditions such as gain and accumulation, a condition must be set to reduce noise to a maximum and a detection signal by a pen to a minimum.

A difference in sensed signals may occur depending on whether or not the low pass filter is used.

The low pass filter is not used in the finger mode, and the low pass filter is used only in the pen mode. That is, in the finger mode, a signal that can be distinguished from noise may be generated even if the low pass filter is not used.

Second, in the pen mode, the touch sensing unit 600 or the touch determination unit 410 may amplify the size of the sensing signal and then generate the raw data using the amplified sensing signals. As the magnitude of the detection signal is amplified, the magnitude of the accumulated detection signals may be amplified as a whole. Accordingly, whether or not each sensing signal is touched by a pen having a small size can be more clearly determined.

Amplifying the size of the sensing signal is related to the ability to resolve touch resolution. In other words, amplifying the size of the sensing signal can be linked to accuracy. The size of the touch electrode (currently 4mm to 4.5mm) cannot be made infinitely small. Therefore, when a small size (1 mm) of the pen touches, the surrounding data is not large, that is, the amount of change is small, and thus whether the pen touches the touch cannot be accurately determined. Therefore, the accuracy is also significantly inferior. To prevent this, the present invention uses a method of amplifying the size of a sensing signal as described above.

In this case, the noise and the size of the raw data (or detection signal) are amplified together.

Accordingly, through various simulations and tests, a gain is calculated in which the size of the noise becomes the minimum and the size of the raw data becomes the maximum. The gain is stored in the touch determination unit 410 or the touch sensing unit 600 so that the touch determination unit 410 or the touch sensing unit 600 is driven according to the calculated gain.

For example, in the finger mode, a gain may be set to 0.125. In the pen mode, when a gain is set to 0.25, an increase in noise may be minimized, and a size of the raw data may be maximized.

Third, in the pen mode, the touch sensing unit 600 or the touch determination unit 410 may increase the cumulative number of detection signals, that is, the number of touch drive signals.

Increasing the number of accumulated detection signals means increasing the number of touch drive signals. When the number of accumulated detection signals is increased, the magnitude of the accumulated detection signals may be increased as a whole. Accordingly, whether or not each sensing signal is touched by a pen having a small size can be more clearly determined.

In this case, as the number of times of accumulation of the detection signal increases, the speed of detecting the touch decreases. Therefore, the number of times of accumulation is set to an appropriate value through various tests and simulations.

Fourth, in the pen mode, the touch sensing unit 600 or the touch determination unit 410 may increase the frequency of the touch driving signal. When the frequency of the touch drive signal is increased, the same effect as the effect of increasing the number of accumulated detection signals can be obtained. Accordingly, the touch by the pen can be more accurately determined.

However, increasing the frequency and increasing the number of accumulations have different meanings. For example, while the frequency is set to 100 KHz to 200 KHz (increase by 10 units) and the cumulative number of times is 1 to 20 (increase by 1 unit), the buffering condition of the capacitance of each touch electrode can be detected. .

In addition, by measuring the signal-to-noise ratio (SNR), the frequency and the number of accumulations may be set so that the best signal-to-noise ratio condition can be detected. That is, preferentially, through various tests and simulations, the frequency and the number of accumulations in the pen mode may be set.

When the frequency is increased, charging slows down and may be caught in a low pass filter (LPF). That is, the frequency is not necessarily increased and, therefore, may be decreased.

Fifth, in the pen mode, the touch sensing unit 600 or the touch determination unit 410 may increase the voltage level of the touch driving signal. For example, since the touch area by the pen is small, the size of the detection signal by the pen is small in the conventional display device, and thus, the presence or absence of the touch by the pen may not be easily determined. However, as described above, when the voltage level of the touch drive signal increases, the magnitude of the detection signal increases, so that the presence or absence of a touch by the pen can be more accurately determined.

Accordingly, the touch by the pen can be more accurately determined.

However, as the voltage level of the touch drive signal increases, the magnitude of the detection signal increases, but the magnitude of noise increases and power consumption increases.

Accordingly, the voltage level is also set to an appropriate value through various tests and simulations.

Next, as a result of the determination (S302), if a touch by the pen is not detected, the touch determination unit 410 and the touch sensing unit 600 determine a touch coordinate in the finger mode (S308).

The function of determining the touch coordinates in the finger mode may be applied as it is to the function of determining the touch coordinates in a current general display device.

Therefore, a detailed description thereof will be omitted.

Finally, the touch determination unit 410 determines whether a change from the pen mode to the finger mode is required (S306). As a result of the determination (S306), when a change to the finger mode is requested, the touch determination unit 410 switches the pen mode to the finger mode. However, as a result of the determination (S306), when the change to the finger mode is not required, the touch determination unit 410 maintains the pen mode as it is.

When switching from the pen mode to the finger mode, the touch determination unit 410 and the touch sensing unit 600 perform a function of determining a touch coordinate in the finger mode.

As described above, there are two methods for the touch determination unit 410 to convert the pen mode to the finger mode.

First, the touch determination unit 410 may change the driving mode to the finger mode when it is determined that there is no touch by the pen for a preset period after the pen mode is selected.

Second, when a mode change signal is received from the external system 900 while the touch determination unit 410 and the pen mode are selected, the driving mode may be switched to the finger mode.

That is, when the pen is not touched, the touch determination unit 410 may automatically or manually switch the driving mode to the finger mode, thereby more accurately determining the presence or absence of a touch by the finger.

The features of the present invention described above are summarized as follows.

In general, the touch sensing unit generates raw data for determining whether or not a touch is present. The touch sensing unit or the touch determining unit recognizes a touch as a touch only when the sensing signal or raw data exceeds a preset threshold. When a user makes a touch using a pen or a small conductive rod, when a palm or hand is placed on the touch panel, the threshold value is exceeded, so the touch determination unit recognizes a touch that the user does not intend.

Accordingly, a display device to which a touch panel using a pen is applied uses a palm rejection function.

The palm rejection function uses a method of removing abnormally detected raw data by using the size, location, and intensity of the touch area. However, by the palm rejection function, when the touch by the pen and the touch by the palm are dynamically changed, it is difficult to effectively remove the touch by the palm.

In order to solve this problem, a method of distinguishing touch by the palm and the pen must be applied by changing the driving conditions in the pen mode and the finger mode.

The size of the detection signal generated when the pen is touched is generally smaller than the size of the detection signal generated when the finger or palm is touched. Therefore, in order to accurately recognize the touch by the pen, the threshold value must be as low as possible.

However, when the threshold value is lowered, when the palm and the pen are touched at the same time, the touch by the palm and the pen is formed at one level, making it difficult to distinguish the touch by the pen.

Accordingly, in the present invention, first, the presence or absence of a touch by the pen is determined using a pattern of received sensing signals. When it is determined that there is a touch by the pen, the touch sensing unit 600 and the touch determination unit 410 are driven under conditions optimized for determining whether or not there is a touch by the pen. Here, the optimized conditions may include the five conditions described above.

In general, as shown on the left side of FIG. 6, when a touch A by a pen and a touch B by a palm occur simultaneously, since values exceeding the threshold are formed at one level, the touch is determined. It is difficult for the unit 410 to clearly distinguish between a touch by a pen and a touch by a palm.

However, in the present invention, as described above, once converted to the pen mode, since the touch determination unit 410 and the touch sensing unit 600 are driven under conditions optimized for determining the presence or absence of a touch by a pen, As shown on the right side of FIG. 6, only the touch A by the pen can be clearly recognized.

In the present invention, while the pen mode is in progress, when a touch by a pen is not input for a preset period, or when a signal requesting conversion to the finger mode is received from the external system 900, the pen mode is Convert to finger mode. When converted to the finger mode, the touch sensing unit 600 and the touch determination unit 410 determine the presence or absence of a touch and a touch coordinate using a general method currently used.

According to the present invention as described above, power consumption can be reduced, and a user can touch using a pen in a more comfortable posture.

Those skilled in the art to which the present invention pertains will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

100: panel 200: gate driver
300: data driver 400: control unit
500: touch panel 600: touch sensing unit
410: touch determination unit

Claims (7)

A touch panel on which touch electrodes are formed;
A touch sensing unit supplying a touch driving signal to the touch panel in a finger mode, receiving sensing signals based on the touch driving signal from the touch panel, and converting the sensing signals into raw data having a digital value; And
By analyzing the raw data, it is determined whether there is a touch by the pen, and when it is determined that there is a touch by the pen, the driving mode of the touch panel is switched from the finger mode to the pen mode, and the touch is performed using the raw data. Including a touch determination unit for determining the touch coordinates in which the touch is generated on the panel,
The touch determination unit,
In the finger mode, when reference row data exceeding a threshold value that can be recognized as a touch is detected, row data of touch electrodes surrounding the reference touch electrode from which the reference row data is detected are stored,
A display device including a touch panel for determining that the reference touch electrode is touched by a pen when it is determined that the raw data of the touch electrodes surrounding the reference touch electrode are gradually decreasing. The method of claim 1,
The touch determination unit,
Determining a mode for selecting the pen mode or the finger mode by analyzing the raw data, and transmitting a touch mode control signal to the touch sensing unit to drive the touch sensing unit in the pen mode or the finger mode according to the selection part;
A touch coordinate determination unit which analyzes the raw data and determines a touch coordinate touched by the touch panel by a finger or a pen; And
A display device with a touch panel including a communication unit for transmitting the touch coordinates to an external system. delete The method of claim 2,
The touch sensing unit,
When the touch mode control signal means the pen mode, a touch drive signal having a frequency, number, or voltage level different from the frequency, number, or voltage level of the touch drive signal in the finger mode is generated to the touch panel. A display device provided with a supply touch panel. The method of claim 2,
The touch sensing unit,
When the touch mode control signal means the pen mode, the raw data is generated after amplifying the size of the sensing signal, or the raw data is generated after filtering the sensing signal using a low pass filter, A display device including a touch panel that transmits the generated raw data to the touch determination unit. The method of claim 1,
The touch determination unit,
After the pen mode is selected, when it is determined that there is no touch by the pen for a preset period, the display device includes a touch panel that switches the driving mode to the finger mode. The method of claim 2,
The touch determination unit,
When the pen mode is selected, when a mode change signal is received from the external system, a display device including a touch panel for converting the driving mode to the finger mode.

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